Claude Code v2.1.321 Update Adds New Model and Bug Fixes

At a glance

Anthropic has released v2.1.321, a new version of its AI coding tool Claude Code. It adds the new default model Claude Fable 5.2 and a feature to specify a settings file for remote control. Many security and error fixes are also included.

Key points

1. 1

   The new model Claude Fable 5.2 has been added and is now the default model. Its context window (the amount of text it can handle at once) is 1 million tokens.

2. 2

   Remote control commands can now specify a settings file. When the file changes, new sessions will not open until a restart.

3. 3

   Fixed an issue where authentication tokens could pass to other servers during MCP login, and an issue where read-only commands ran outside the sandbox.

4. 4

   Fixed several errors in notebook editing, file modification, and permission checks, where the wrong file could be changed or actions ran without asking.

Why it matters

Because this tool directly handles files and commands on a computer, security fixes and the default model change directly affect user data and work results.